This study examined the effect of social familiarity on salivary cortisol and social anxiety/stress for a sample of children with high-functioning autism spectrum disorders. The relationship between self-reported social anxiety/stress and salivary cortisol was also examined. Participants interacted with a familiar peer on one occasion and an unfamiliar peer on another occasion. Data were collected using salivary cortisol and a scale measuring subjective stress. Results indicated a significant condition by order interaction for salivary cortisol levels, while self-rated stress did not differ significantly across situations. A mild-moderate correlation was found between self-reported distress and salivary cortisol within each condition. Examination of self-rated distress vs. cortisol scatter plots suggested a more complex relationship than the correlation coefficient could adequately convey.